Diagenetic transformation of organic matter in the Holocene sediments of the Black Sea: pyrolysis data

The article presents the results of pyrolysis (Rock-Eval) and pyrolysis-gas chromatography-mass spectrometry analysis of organic matter (OM) in the Holocene sediments of the Black Sea. The studied samples represent two parts of the sedimentary column: coccolith ooze with 2.8% Corg at the top and sapropels oozes with 8.5% Corg at the bottom. The deposition of Holocene sediments was inferred to take place under euxinic conditions, which are more favorable for organic-matter preservation and sapropel deposition during the Old Black Sea stage. The results show that the modern processes of microbially mediated methane oxidation in the Old Black Sea oozes are interpreted as the main cause of their apparently lower degree of diagenetic transformation as compared to that of coccolith oozes.